How to set origin of multiple objects at the same time?
Well I'm not sure of a good way to do this, you can try to select all your arrows, and then select the one with the correct origin, then press CTRL+L, and select "Object Data" from the list.. Unfortunately this is not ideal, as it also copies all other object data such as materials and UVs, effectively making all the arrows instances of the active one.


You can then select all the arrows again, then press U on the keyboard, and select "Objects and Data" from the list, to make all the arrows mesh data single users again, and not instanced..